A significant discovery
In the Soa Basin of central Flores, a layer of sandstone records the history of the deep past. In 2014, researchers excavating at a site called Mata Menge pulled a fossilized mandible fragment and six teeth from this layer. These were fossils; they belonged to a tiny hominin that lived around 700,000 years ago. The age was determined by dating the layers of volcanic ash that sandwiched the fossil-bearing sandstone. Methods like argon-argon dating and fission track dating on the volcanic deposits provided a secure timeframe for when these individuals lived.
The fossils, which represent at least three separate individuals including two children, are the oldest hominin remains ever found on the island of Flores. Their discovery dramatically pushed back the known timeline of hominin occupation. Their anatomy suggests they were direct ancestors of Homo floresiensis, the famous "hobbit" discovered in 2003 at Liang Bua cave, 74 kilometers away. The Mata Menge jaw is about 20% smaller than the already small mandible of the much later Liang Bua hobbit, indicating that extreme shrinkage, a process called insular dwarfism—was well underway half a million years earlier than previously known. A recently found 700,000-year-old humerus (upper arm bone) from the site belonged to an adult estimated to be only about 100 cm tall.